Key Terms humerus : The bone of the upper arm. The proximal portion of the humerus can be divided into three parts. The rounded humeral head projects medially and articulates with the glenoid cavity of the scapula. Immediately adjacent to the head is the narrower anatomical neck, which allows for a wider range of movements of the head within the shoulder joint. Finally, the greater and lesser tubercles are found at the most superior end of the main shaft of the humerus.
Arm pain is defined as discomfort or pain experienced anywhere throughout your arm. It can include pain in your wrist, elbow, and rotator cuff. A humerus fracture is a break in the large bone of your upper arm. There are several types of humerus fractures, depending on the location of the…. But pain in one part of the body can sometimes originate elsewhere.
A pain in your left arm could…. When something goes wrong with your shoulder, it hampers your ability to move freely and can cause a great deal of pain and discomfort.
In many cases…. Shoulder mobility stretches and exercises can help improve shoulder flexibility, reduce tension, increase range of motion, and prevent injury. Bone pain is an extreme tenderness or aching in one or more bones. A recessed maxilla can cause cosmetic issues like flat cheekbones and a prominent jaw, and lead to dental problems, speech issues, and obstructed….
If you do tear a meniscus, you might be tempted to "walk it off. A lateral pelvic tilt is when one hip is higher than the other. Learn about five exercises that can help with this condition. Both the greater and lesser tubercles serve as attachment sites for muscles that act across the shoulder joint. The deltoid tuberosity is a roughened, V-shaped region located on the lateral side in the middle of the humerus shaft.
As its name indicates, it is the site of attachment for the deltoid muscle. Distally, the humerus becomes flattened. The prominent bony projection on the medial side is the medial epicondyle of the humerus. The much smaller lateral epicondyle of the humerus is found on the lateral side of the distal humerus. All of these areas are attachment points for muscles that act on the forearm, wrist, and hand.
The powerful grasping muscles of the anterior forearm arise from the medial epicondyle, which is thus larger and more robust than the lateral epicondyle that gives rise to the weaker posterior forearm muscles. The distal end of the humerus has two articulation areas, which join the ulna and radius bones of the forearm to form the elbow joint.
The capitulum articulates with the radius bone of the forearm. Just above these bony areas are two small depressions. These spaces accommodate the forearm bones when the elbow is fully bent flexed.
Superior to the trochlea is the coronoid fossa , which receives the coronoid process of the ulna, and above the capitulum is the radial fossa , which receives the head of the radius when the elbow is flexed.
Similarly, the posterior humerus has the olecranon fossa , a larger depression that receives the olecranon process of the ulna when the forearm is fully extended.
The ulna is the medial bone of the forearm. It runs parallel to the radius, which is the lateral bone of the forearm Figure 6. The proximal end of the ulna resembles a crescent wrench with its large, C-shaped trochlear notch. This region articulates with the trochlea of the humerus as part of the elbow joint. The inferior margin of the trochlear notch is formed by a prominent lip of bone called the coronoid process of the ulna.
Just below this on the anterior ulna is a roughened area called the ulnar tuberosity. To the lateral side and slightly inferior to the trochlear notch is a small, smooth area called the radial notch of the ulna. This area is the site of articulation between the proximal radius and the ulna, forming the proximal radioulnar joint. The posterior and superior portions of the proximal ulna make up the olecranon process , which forms the bony tip of the elbow.
More distal is the shaft of the ulna. The small, rounded area that forms the distal end is the head of the ulna. Projecting from the posterior side of the ulnar head is the styloid process of the ulna , a short bony projection. Immediately adjacent to the ulnar notch, the radius articulates with the scaphoid and lunate carpal bones to form part of the wrist.
Each hand consists of 27 bones, divided between the wrist bones carpals , the palm bones metacarpals , and the finger bones phalanges. Carpals of the left hand : There are eight carpal bones in each wrist: scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, and hamate. The hand contains 27 bones.
Each one belongs to one of three regions: the carpals, wrist , the metacarpals, the palm , and the phalanges the digits. The eight, irregularly shaped carpals are the most proximal bones of the hand. The carpals are often split into two rows, the proximal row containing the scaphoid, lunate, triquetrum, and pisiform, moving lateral to medial. The scaphoid and lunate articulate with the radius, and the lunate and triquetrum articulate with the articular disk of the wrist.
The pisiform carpal is a sesamoid bone, located within a tendon and is not involved in movement at the wrist. The distal row contains the trapezium, trapezoid, capitate, and hamate, moving lateral to medial. The trapezium articulates with the scaphoid proximally and the first, thumb, and second metacarpal distally.
The trapezoid articulates with the scaphoid proximally and the second metacarpal distally. Metacarpal bones of the left hand : The metacarpals connect the carpal bones of the wrist with the phalanges finger bones. The capitate articulates with the scaphoid and lunate proximally and the third and fourth metacarpal.
Finally, the hamate articulates with the lunate and triquetral proximally and the fourth and fifth, little finger, metacarpals distally. The hand contains five metacarpal bones that articulate proximally with the carpals and distally with the proximal phalanges.
They are numbered moving lateral to medial, and start with the thumb, which is metacarpal I, and end with metacarpal V, the little finger. Each metacarpal consists of a base, shaft, and head, with the concave lateral and medial borders of the shaft allowing attachment of the interossei muscles. The digits are named in a similar fashion to the metacarpals, moving lateral to medial, and starting at the thumb.
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